Powered lower extremity orthotics, such as powered leg braces or a powered human exoskeleton, can allow a paraplegic patient to walk, but require a means by which to communicate what action the exoskeleton should make. Because some of the users are completely paralyzed in one or both legs, the exoskeleton control system must determine which leg the user would like to move and how they would like to move it before the exoskeleton can make the proper motion. These functions are achieved through a human machine interface (HMI) which translates motions by the person into actions by the orthotic. The invention is concerned with the structure and operation of HMIs for lower extremity orthotics.